Lightweight Inflation Device

ABSTRACT

An inflator for inflating an air mattress or the like may include a housing, a rotor, a stator, an electric motor, and at least one battery. The rotor may be contained within the housing and include a first circuit of fan blades and a second circuit of fan blades. The first and second circuits of fan blades may respectively generate centrifugal and axial flows of air when the electric motor rotates the rotor with respect to the stator. The stator may be contained within the housing and include a third circuit of fan blades. The at least one battery may power the electric motor. The at least one battery and the electric motor may also be contained within the housing.

BACKGROUND 1. The Field of the Invention

This invention relates to inflation of air bladders and, more particularly, to novel systems and methods for a lightweight, readily portable, inflation device.

2. The Background Art

Various devices require inflation of one or more air bladders before they are ready to use. For example, sleeping pads, ultra-light air mattresses, pillows, or the like may include one or more air bladders that need to be inflated. Known devices and methods for inflating such devices include manual inflation and operating a pumping device (e.g., a manually powered pump or a pump driven by an electric motor).

Manually powered pumping devices (e.g., bellows-style compression sacks) are often large enough to move a significant volume of air with each manual compression of the sack. However, this size can make such devices somewhat unwieldy and difficult to transport. Electrically powered pumping devices, on the other hand, frequently include a large and heavy electric motor to run the pump. Such motors consume significant electrical energy and often require access to a standard electrical outlet or a large battery pack.

While such conventional devices and methods for inflation have been satisfactory in some respects, they have also presented drawbacks in both convenience and portability. Such drawbacks are particularly noticeable in the fields of backpacking, camping, or other remote outdoor activities, where access to standard electrical outlets is typically non-existent and the weight of large motors and/or battery packs makes it impractical to transport them to remote locations.

BRIEF SUMMARY OF THE INVENTION

In view of the foregoing, a method and apparatus are disclosed in selected embodiments of the present invention as including a lightweight inflation device. Such an inflation device may be or include a dual-stage compressor assembly selectively outputting a low-pressure airflow for efficiently inflating an air bladder. An inflation device in accordance with the present invention may be particularly advantageous for quickly and easily inflating an air bladder forming part of a sleeping pad, ultra-light air mattress, pillow, or other article that may be used for backpacking, camping, or other outdoor activities due to the inflation device being compact, lightweight, and easily portable.

In selected embodiments, an inflation device may conserve energy so that a power source corresponding thereto may be small and yet last for a sufficient period of time. For example, when an inflation device is driven by an electric motor powered by one or more batteries, the device may be sufficiently efficient to support multiple inflation cycles between charging or replacing the one or more batteries.

In certain embodiments, an inflation device may include a housing, a rotor, a stator, an electric motor, and one or more batteries. The rotor may be contained within the housing. The rotor may define a central axis (i.e., an axis about which the rotor may rotate) and comprise first and second circuits of fan blades. The first and second circuits of fan blades may respectively generate centrifugal and axial flows of air when the rotor is rotated about the central axis.

In selected embodiments, the rotor may include a central hub having a circumference. The first circuit of fan blades may be located inboard of the circumference. The second circuit of fan blades may be located outboard of the circumference. Alternatively, or in addition thereto, the central hub of a rotor may have a front face and a side wall. The first circuit of fan blades may extend axially away from the front face. The second circuit of fan blades may extend radially away from the side wall.

The stator, the electric motor, and the one or more batteries may also be contained within the housing. The stator may comprise a third circuit of fan blades extending radially away from the central axis. The electric motor may generate relative rotation of a rotor with respect to the stator about the central axis. The one or more batteries may power the electric motor.

The housing may comprise an inlet and an outlet. The first circuit of fan blades of the rotor may be downstream of the inlet. The second circuit of fan blades of the rotor may be downstream of the first circuit of fan blades. The third circuit of fan blades (i.e., fan blades corresponding to a stator) may be downstream of the second circuit of fan blades. The outlet may be downstream of the third circuit of fan blades.

In certain embodiments, an inflation device may include a restrictor positioned between the inlet and the first circuit of fan blades. The restrictor may require that air flowing from the inlet to the outlet pass through a central aperture. The central aperture may have a diameter that is less than or equal to an outer diameter of the first circuit of fan blades of the rotor. Alternatively, the central aperture may have a diameter that is less than or equal to an inner diameter of the second circuit of fan blades of the rotor. In either case, the central aperture of the restrictor may preferentially direct a flow of air toward the first circuit of fan blades corresponding to the rotor to ensure that substantially all of the flow of air entering through the inlet may have a desired centrifugal motion induced therein.

A method for using an inflation device may include obtaining an inflation device having an inlet, a rotor, a stator, an electric motor, and an outlet. The rotor may define a central axis and include a first circuit of fan blades and a second circuit of fan blades. The stator may include a third circuit of fan blades extending radially away from the central axis. The electric motor may be configured to provide relative rotation of the rotor with respect to the stator about the central axis.

Once the inflation device is obtained, the method may continue with powering the electric motor to generate a flow of air from the inlet to the outlet. While the inflation device is being powered, the first circuit of fan blades may produce a centrifugal compression on the flow of air and the second circuit of fan blades may produce an axial compression on the flow of air. The centrifugal compression may precede the axial compression. Shortly before or after such powering, the inflation device may be applied to a port, nozzle, valve, or the like corresponding to an air bladder. If the outlet of the inflation device is applied to the port, nozzle, valve, or the like, the air bladder may be inflated. Conversely, if the inlet of the inflation device is applied to the port, nozzle, valve, or the like, the air bladder may be deflated.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described with additional specificity and detail through use of the accompanying drawings in which:

FIG. 1 is a perspective view of one embodiment of an inflation device in accordance with the present invention;

FIG. 2 is another perspective view of the inflation device of FIG. 1;

FIG. 3 is a first end view of the inflation device of FIG. 1;

FIG. 4 is a second, opposite end view of the inflation device of FIG. 1;

FIG. 5 is a first side view of the inflation device of FIG. 1;

FIG. 6 is a second, opposite side view of the inflation device of FIG. 1;

FIG. 7 is a front view of the inflation device of FIG. 1;

FIG. 8 is a back view of the inflation device of FIG. 1;

FIG. 9 is an exploded perspective view of the housing of the inflation device of FIG. 1;

FIG. 10 is a cross-sectional view of the inflation device of FIG. 1;

FIG. 11 is another cross-sectional view of the inflation device of FIG. 1;

FIG. 12 is a partial cross-sectional view of the inflation device of FIG. 1 showing a flow of air therethrough;

FIG. 13 is a front view of the rotor of the inflation device of FIG. 1;

FIG. 14 is a perspective view of the rotor of the inflation device of FIG. 1;

FIG. 15 is another perspective view of the rotor of the inflation device of FIG. 1;

FIG. 16 is a perspective view of the stator of the inflation device of FIG. 1;

FIG. 17 is another perspective view of the stator of the inflation device of FIG. 1;

FIG. 18 is a cut-away perspective view of the restrictor of the inflation device of FIG. 1;

FIG. 19 is a cross-sectional view of the outlet interface of the inflation device of FIG. 1;

FIG. 20 is a cross-sectional view of the inlet interface of the inflation device of FIG. 1;

FIG. 21 is a perspective view of an alternative embodiment of an inflation device in accordance with the present invention;

FIG. 22 is another perspective view of the inflation device of FIG. 21;

FIG. 23 is a first end view of the inflation device of FIG. 21;

FIG. 24 is a second, opposite end view of the inflation device of FIG. 21;

FIG. 25 is a first side view of the inflation device of FIG. 21;

FIG. 26 is a second, opposite side view of the inflation device of FIG. 21;

FIG. 27 is a front view of the inflation device of FIG. 21; and

FIG. 28 is a back view of the inflation device of FIG. 21.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

It will be readily understood that the components of the present invention, as generally described and illustrated in the drawings herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the system and method of the present invention, as represented in the drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of various embodiments of the invention. The illustrated embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.

Referring to FIGS. 1-9, in selected embodiments, an inflation device 10 in accordance with the present invention may include a housing 12. A housing 12 may protect and support (e.g., provide mounting locations for) one or more interior components of an inflation device 10. Accordingly, a housing 12 may be or function as a frame or body of an inflation device 10. Additionally, a housing 12 may define the exterior look and feel of an inflation device 10. In certain embodiments, a housing 12 may present a generally smoothly contoured exterior surface lacking sharp or pointed corners. This may prevent unwanted wear on the inflation device 10 and on any bag, pocket, or the like in which the inflation device 10 is stored or carried.

A housing 12 may be formed of any material having a suitable weight, strength, rigidity, cost, and formability. Suitable materials for a housing 12 may include metals, metal alloys, polymers, and composite materials. For example, in selected embodiments, a housing 12 may comprise polymeric material formed in a molding (e.g., injection molding) process.

A housing 12 may comprise multiple components. For example, in certain embodiments, a housing 12 may comprise a base 14, an end cap 16, and a hatch cover 18. A base 14 may form a primary or largest component of a housing 12. In certain embodiments, for ease of manufacture, a base 14 may be an assembly of multiple parts that are secured (e.g., glued, bonded, ultrasonically welded, or the like) together. A base 14 may form an end portion and multiple sides (e.g., side, front, or back surfaces) of a housing 12. An end cap 16 may be selectively securable to a base 14 and form an end portion of a housing 12. A hatch cover 18 may selectively cover a hatch opening 20 in a base 14. A hatch opening 20 and a hatch cover 18 may cooperate to provide a user of an inflation device 10 with ready access to certain components contained within a housing 12. For example, in certain embodiments, a hatch opening 20 and a hatch cover 18 may enable a user to swap out one or more batteries contained within a housing 12.

In selected embodiments, a housing 12 may include multiple apertures. For example, as noted above, a housing 12 may include a hatch opening 20 providing access to one or more components contained within a housing 12. Alternatively, or in addition to a hatch opening 20, a housing 12 may include one or more apertures 22 for receiving one or more fasteners, a user-interface aperture 24, an inlet aperture 26, an outlet aperture 28, or the like or a combination or sub-combination thereof.

In certain embodiments, one or more apertures 22 for receiving one or more fasteners may include apertures 22 for receiving fasteners that hold various components of a housing 12 together. For example, an end cap 16 may include one or more apertures 22 for receiving one or more fasteners (e.g., one or more threaded fasteners) that secure the end cap 16 to a base 14. Alternatively, an end cap 16 may be secured to a base 14 by some other mechanism (e.g., a bonding agent or solvent, ultrasonic welding, or the like). Accordingly, in certain embodiments, an end cap 16 need not include one or more apertures 22 for receiving one or more fasteners.

A user-interface aperture 24 may provide a location for mounting a user interface. A user interface may enable a user to control one or more aspects or functions of an inflation device 10. For example, in selected embodiments, a user interface may be or comprise a switch. By manipulating an exterior or exposed portion 30 of a switch, a user may turn an inflation device 10 on or off. Accordingly, in certain embodiments, a user-interface aperture 24 may provide a location for mounting an exterior or exposed portion 30 of a switch.

In selected embodiments, an exterior or exposed portion 30 of a switch may be a slide that is largely recessed within a user-interface aperture 24. Such recessing may reduce the likelihood of the exterior or exposed portion 30 being inadvertently actuated (e.g., while the inflation device 10 is being carried in a sack, pocket, or the like). Accordingly, in certain embodiments, recessing an exterior or exposed portion 30 within a user-interface aperture 24 may protect one or more batteries powering an inflation device 10 from being inadvertently and prematurely depleted.

Inlet and outlet apertures 26 and 28 in accordance with the present invention may be defined in terms of a flow of air generated by the corresponding inflation device 10. Accordingly, when an inflation device 10 is turned on and operating, air may be taken into an inflation device 10 through an inlet aperture 26 and may be exhausted out of the inflation device 10 through an outlet aperture 28. Thus, a flow of air generated by an inflation device 10 may pass through the inflation device 10 from the inlet aperture 26 to the outlet aperture 28.

In selected embodiments, it may be necessary or desirable to secure an inflation device 10 to an air bladder (e.g., an air bladder contained within or forming an inflatable mattress, pillow, or the like). For example, an air bladder may have a port, nozzle, valve, or the like (hereinafter “port”) through which air may be injected to inflate the air bladder and/or out of which air may be exhausted to deflate the air bladder. Accordingly, in selected embodiments, an inflation device 10 may selectively engage (e.g., hold to, seal against, or the like) a port of an air bladder to efficiently inject air into the corresponding air bladder.

In selected embodiments, an inflation device 10 may include an outlet interface 32. An outlet interface 32 may interface between an outlet aperture 28 of a housing 12 and a port of an air bladder. In certain embodiments, an outlet interface 32 may be formed of elastomeric material (e.g., silicone rubber or the like). Accordingly, an outlet interface 32 may resiliently flex, stretch, or the like to accommodate, grip, or seal against a port of an air bladder. An outlet interface 32 may also seal against the housing 12 of an inflation device 10. Accordingly, an outlet interface 32 may enable an inflation device 10 to efficiently direct a flow of air into an air bladder.

In certain embodiments, an inflation device 10 may include an inlet interface 34. An inlet interface 34 may be very similar (e.g., identical) to an outlet interface 32. For example, an inlet interface 34 may interface between an inlet aperture 26 of a housing 12 and a port of an air bladder. Additionally, an inlet interface 34 may also be formed of elastomeric material (e.g., silicone rubber or the like). Accordingly, an inlet interface 34 may resiliently flex, stretch, or the like to accommodate, grip, or seal against a port of an air bladder. An inlet interface 34 may also seal against the housing 12 of an inflation device 10. An inlet interface 34 may, therefore, enable an inflation device 10 to efficiently extract a flow of air from an air bladder.

Accordingly, in situations where an inflation device 10 is turned on and operating and an outlet interface 32 thereof is applied to a port of an air bladder, air may be injected by the inflation device 10 into the air bladder. Conversely, in situations where an inflation device 10 is turned on and operating and an inlet interface 34 thereof is applied to a port of an air bladder, air may be extracted by the inflation device 10 from the air bladder. Thus, an inflation device 10 in accordance with the present invention may be used to inflate and/or deflate an air bladder.

Referring to FIGS. 10 and 11, in selected embodiments, an inflation device 10 in accordance with the present invention may include a rotor 36, a stator 38, and a drive mechanism 40 positioned and connected to selectively induce relative rotation of the rotor 36 with respect to the stator 38. In certain embodiments, a drive mechanism 40 may be or comprise a motor (e.g., an electric motor) having a drive shaft 42. A drive shaft 42 and/or rotor 36 may define a central axis 44. For example, a drive shaft 42 may extend along and rotate about a central axis 44. Similarly, a rotor 36 may rotate about the central axis 44. Accordingly, a central axis 44 of an inflation device 10 may not correspond to the center (i.e., geometric center, center of mass, or the like) of the inflation device 10, but rather to an axis of rotation about which one or more components of the inflation device 10 rotate.

In certain embodiments, a rotor 36 may include a central hub 46, a first circuit of fan blades 48, and a second circuit of fan blades 50. The first circuit of fan blades 48 may connect to the central hub 46 and extend axially (i.e., in a direction parallel to the central axis 44) away therefrom. The second circuit of fan blades 50 may connect to the central hub 46 and extend radially (i.e., radially with respect to the central axis 44) away therefrom.

A stator 38 may include an outer wall 52, an inner hub 54, and a circuit of fan blades 56. In selected embodiments, an outer wall 52 may be cylindrical. An inner hub 54 may be positioned interior to and co-axial with respect to the outer wall 52. A circuit of fan blades 56 may extend radially to connect an inner hub 54 to an outer wall 52. In certain embodiments, an inner hub 54 may be or function as a mount for a drive mechanism 40. For example, an inner hub 54 may have a cavity into which a drive mechanism 40 may be inserted and secured. Accordingly, in selected embodiments, a drive shaft 42 may extend axially away from an inner hub 54 to engage a rotor 36.

In certain embodiments, an inflation device 10 may include a cover 58. A cover 58 may cooperate with (e.g., align with and secure to) an inner hub 54 to enclose and/or protect a drive mechanism 40.

An inflation device 10 may include a restrictor 60. In selected embodiments, a restrictor 60 may include an outer wall 62, a central aperture 64, and a barrier 66. In certain embodiments, an outer wall 62 may be cylindrical. A central aperture 64 may be positioned interior to and co-axial with respect to the outer wall 62. A barrier 66 may extend radially to block off all axial flow of air through the restrictor 60 except through the central aperture 64. Accordingly, a restrictor 60 may require air flowing axially through a restrictor 60 to pass through the central aperture 64.

An outer wall 62 of a restrictor 60 may cooperate with (e.g., align with and secure to) an outer wall 52 of a stator 38 to form a conduit through which air must pass in order to travel from an inlet aperture 26 to an outlet aperture 28. Accordingly, in certain embodiments, an upstream end of an outer wall 62 of a restrictor 60 may be positioned proximate an inlet aperture 26, a downstream end of the outer wall 62 of the restrictor 60 may engage an upstream end of an outer wall 52 of a stator 38, and a downstream end of the outer wall 52 of the stator 38 may be positioned proximate an outlet aperture 28.

In selected embodiments, an upstream end of an outer wall 62 of a restrictor 60 may engage an inlet interface 34. Accordingly, an inlet interface 34 may hold, secure, and/or seal the upstream end of an outer wall 62 of a restrictor 60 with respect to a housing 12. Similarly, a downstream end of the outer wall 52 of a stator 38 may engage an outlet interface 34. Accordingly, an outlet interface 34 may hold, secure, and/or seal the downstream end of the outer wall 52 of the stator 38 with respect to the housing 12.

In embodiments where the inlet and outlet interfaces 34, 32 are formed of elastomeric material, the inlet and outlet interfaces 34, 32 may at least partially mechanically isolate a rotor 36, stator 38, drive mechanism 40, and restrictor 60 from the rest of an inflation device 10. That is, vibrations associated with such components 36, 38, 40, 60 may be at least partially absorbed by the inlet and outlet interfaces 34, 32 so as to not be completely transmitted by the inlet and outlet interface 34, 32 on to the rest of the inflation device 10.

A base 14 may include one or more apertures 68 for receiving one or more fasteners. For example, in certain embodiments, one or more apertures 68 in a base 14 may align with one or more corresponding apertures 22 in an end cap 16. Accordingly, the apertures 22, 68 may enable one or more fasteners to be inserted to secure an end cap 16 to a base 14. Alternatively, one or more apertures 68 may receive alignment pins that extend from (e.g., monolithically extend from) an end cap 16. Such pins or the alignment produced thereby may facilitate a securement (e.g., an ultrasonic welding or bonding) of an end cap 16 to a base 14.

In selected embodiments, a separator 70 may extend within a housing 12 (e.g., within a base 14). A separator 70 may define a space for receiving and securing one or more batteries 72. A separator 70 may be an integral part of a base 14. Alternatively, a separator 70 may be a separate component. For example, in an assembly process, a separator 70 may be inserted within grooves 74 formed within a base 14.

In certain embodiments, a separator 70 may perform multiple functions. For example, in addition to defining a space for receiving and securing one or more batteries 72, a separator 70 may be or include a circuit board (e.g., a printed circuit board) configured to support, enable, or provide a desired electrical operation of an inflation device 10. For example, battery contacts may electrically connect to one side of a separator 70 configured as a circuit board, while a micro switch (e.g., a switch actuated by an exterior or exposed portion 30) may be electrically connected to an opposite side of the separator 70.

In selected embodiments, a base 14 and hatch cover 18 may have an interlocking groove and rail system. For example, each side edge of a hatch cover 18 may have a groove 76 formed therein. The groove 76 may be shaped and sized to engage and slide axially along a corresponding rail 78 formed in the base 14. This may enable a user to quickly and easily access (e.g., replace) one or more batteries 72 contained within a housing 12.

Referring to FIG. 12, in selected embodiments, a first circuit of fan blades 48 corresponding to a rotor 36 may be positioned downstream from an inlet aperture 26. A second circuit of fan blades 50 corresponding to the rotor 36 may be positioned downstream of the first circuit of fan blades 48. A circuit of fan blades 56 corresponding to a stator 38 may be positioned downstream of the second circuit of fan blades 50. An outlet aperture 28 may be positioned downstream of the circuit of fan blades 56 corresponding to a stator 38. Accordingly, in operation, a flow 80 of air entering an inflation device 10 through an inlet aperture 26 (e.g., through a central aperture 82 of an inlet interface 34) may encounter in order a first circuit of fan blades 48 corresponding to a rotor 36, a second circuit of fan blades 50 corresponding to the rotor 36, and a circuit of fan blades 56 corresponding to a stator 38 before exiting the inflation device 10 through an outlet aperture 28 (e.g., through a central aperture 84 of an outlet interface 32).

In certain embodiments, the first circuit of fan blades 48 corresponding to a rotor 36 may be shaped to generate a primarily centrifugal motion 86 in the flow 80 of air. Accordingly, the first circuit of fan blades 48 corresponding to a rotor 36 may perform a first stage, centrifugal compression. The second circuit of fan blades 50 corresponding to a rotor 36 may be shaped to generate a primarily axial motion 88 in the flow 80 of air. Accordingly, the second circuit of fan blades 50 corresponding to a rotor 36 may perform a second stage, axial compression. The circuit of fan blades 56 corresponding to a stator 38 may tend to remove from the flow 80 of air some portion of the rotational motion (e.g., rotation about the central axis 44) imparted by a rotor 36 and, thereby, improve the compressive effect (e.g., the axial compression) produced by the rotor 36.

Referring to FIGS. 13-15, a rotor 36 may have an outer diameter 90 defined by the radially distal extremes of the various fan blades 50 that form the second circuit of fan blades 50 of the rotor 36. In selected embodiments, the outer diameter 90 of a rotor 36 may be slightly less than an inner diameter of an outer wall 52 of a stator 38. This clearance may enable a rotor 36 to rotate about the central axis 44 within the outer wall 52 without unwanted rubbing, contact, or the like with the outer wall 52. In certain embodiments, an outer diameter 90 of a rotor 36 may be about thirty millimeters.

A central hub 46 of a rotor 36 may have an outer diameter 92 and a corresponding outer circumference. In certain embodiments, an outer diameter 92 of a central hub 46 may be about fourteen millimeters. In selected embodiments, the first circuit of fan blades 48 corresponding to a rotor 36 may be located inboard of the outer circumference of the central hub 46. Conversely, the second circuit of fan blades 50 corresponding to a rotor 36 may be located outboard of this outer circumference.

Alternatively, or in addition thereto, a central hub 46 or a rotor 36 may have a front face 94 and a side wall 96 (e.g., a flat front face and a cylindrical side wall). The first circuit of fan blades 48 corresponding to a rotor 36 may extend axially forward (i.e., upstream) away from the front face 94 of a central hub 46. Conversely, the second circuit of fan blades 50 corresponding to a rotor 36 may extend radially away from the side wall 96 of the central hub 46.

In selected embodiments, an underside of a central hub 46 of a rotor 36 may include an aperture 98 for receiving a drive shaft 42 of a drive mechanism 40. Such an arrangement may enable a drive mechanism 40 to induce rotation of a rotor 36.

In the illustrated embodiment, a first circuit of fan blades 48 includes twelve fan blades 48 arranged in a circle. However, in other embodiments, more or fewer fan blades 48 may be included in the first circuit. The fan blades 48 may be sized, shaped, and positioned to “scoop” air from a central or interior location and propel it radially outward.

In the illustrated embodiments, a second circuit of fan blades 50 includes six fan blades 50 arranged in a circle. However, in other embodiments, more or fewer fan blades 50 may be included in the second circuit. Each of the fan blades 50 of a second circuit may define an angle of attack with respect to the surrounding air, given the direction of rotation of the corresponding rotor 36. In certain embodiments, an angle of attack at a root of the fan blades 50 may be about thirty degrees and an angle of attack at a tip of the fan blades 50 may be about fifteen degrees. Accordingly, the fan blades 50 may have a significant amount of “washout” with a smooth transition in angle of attack from root to tip. In other embodiments, the angles of attack at the root and tip may be different from those set forth hereinabove.

Referring to FIGS. 16 and 17, a cavity 100 formed within an inner hub 54 of a stator 38 may be shaped to receive a drive mechanism 40. In selected embodiments, a cavity 100 may include one or more features that prevent a main body of an installed drive mechanism 40 from rotating with respect to a stator 38. For example, a cavity 100 may include blocking 102 or one or more keys 102 that may extend to abut or engage a body of a drive mechanism 40 and resist rotation thereof with respect to a stator 38.

In certain embodiments, a front face 104 of an inner hub 54 may define one end of a cavity 100. A front face 104 of an inner hub 54 may have one or more apertures extending therethrough. For example, a front face 104 of an inner hub 54 may have a central aperture 106 through which a drive shaft 42 may extend to engage a rotor 36. One or more other apertures 108 in a front face 104 of an inner hub 54 may provide venting (e.g., to aid in cooling a drive mechanism 40) and/or locations for one or more fasteners (e.g., threaded fasteners) to extend to engage and axially secure a drive mechanism 40 in place.

In the illustrated embodiments, a circuit of fan blades 56 corresponding to a stator 38 includes twelve fan blades 56 arranged in a circle. However, in other embodiments, more or fewer fan blades 56 may be included within a stator 38. Each of the fan blades 56 of a stator may define an angle of attack with respect to the axial direction (e.g., a direction extending parallel to the central axis 44). In certain embodiments, an angle of attack at a root of the fan blades 56 may be about negative twenty-two degrees and an angle of attack at a tip of the fan blades 50 may be about negative forty-five degrees. Accordingly, the fan blades 56 may have a significant amount of negative or reverse “washout” with a smooth transition in angle of attack from root to tip. In other embodiments, the angles of attack at the root and tip may be different from those set forth hereinabove.

The fan blades 56 of a stator 38 may be oriented and located with respect to a rotor 36 to remove from a flow 80 of air some desired portion of the rotational motion (e.g., rotation about the central axis 44) imparted by the rotor 36. This may increase the compressive effect produced by an inflation device 10. In certain embodiments, an axial spacing between a trailing edge of a fan blade 48 of a second circuit of a rotor 36 and a leading edge of a fan blade 56 of a stator 38 may be about 2.5 mm.

Referring to FIG. 18, a restrictor 60 may be positioned between an inlet aperture 26 and a first circuit of fan blades 48 corresponding to a rotor 36. A restrictor 60 may require that a flow 80 of air from the inlet aperture 26 to the outlet aperture 28 pass through a central aperture 64. A central aperture 64 may have a diameter 110 that is less than or equal to an outer diameter of the first circuit of fan blades 48 corresponding to a rotor 36. This may equate to a central aperture 64 having a diameter 110 that is less than or equal to an outer diameter 92 of a central hub 46 to a rotor 36. Alternatively, or in addition thereto, a central aperture 64 may have a diameter 110 that is less than or equal to an inner diameter of the second circuit of fan blades 50 corresponding to a rotor 36. This may also equate to a central aperture 64 having a diameter 110 that is less than or equal to an outer diameter 92 of a central hub 46 to a rotor 36. Accordingly, a restrictor 60 may preferentially direct a flow 80 of air toward the first circuit of fan blades 48 corresponding to a rotor 36. This may ensure that substantially all of a flow 80 of air entering through an inlet aperture 26 may have a desired centrifugal motion 86 induced therein.

In selected embodiments, one or more elements 112 may extend at least partially across a central aperture 64 of a restrictor 60. For example, three elements 112 may extend radially and meet at a center point of a central aperture 64. Such elements 112 may block foreign objects from being ingested by or inserted within an inflation device 10. This may prevent the foreign objects from clogging or damaging the inflation device 10. It may also protect the foreign object (e.g., a finger) from being damaged.

Referring to FIGS. 19 and 20, in selected embodiments, one or both of an outlet interface 32 and an inlet interface 34 may be sized and shaped to easily receive and engage a port of an air bladder. For example, one or both of an outlet interface 32 and an inlet interface 34 may include a radiused, chamfered, or otherwise smoothed or broken edge 114 to ease the transition of a port into a respective aperture 84, 82 of the outlet and inlet interfaces 32, 34. Alternatively, or in addition thereto, one or both of an outlet interface 32 and an inlet interface 34 may include a groove 116 or recess 116 that is shaped to selectively receive and retain a complementary extension of a port. In such embodiments, an elasticity of an outlet and/or inlet interface 32, 34 formed of elastomeric material may enable the outlet and/or inlet interface 32, 34 to expand 118 to receive a port with such an extension, contract to grip the port and extension, and expand 118 to facilitate removal of the port and extension.

Referring to FIGS. 21-28, in selected embodiments, an outer surface of a housing 12 (or some portion of an outer surface of a housing 12) may have a sand-blasted, stippled, or otherwise textured finish. To produce such a finish in a molding process, a housing 12 may need to include a certain amount of draft. This may make it easier to extract one or more textured parts of a housing 12 from a mold. In the illustrated embodiment, to provide the draft necessary to accommodate a sand-blasted, stippled, or otherwise textured finish, an end of a housing 12 corresponding to a base 14 may be narrower (e.g., in two dimensions) than an end corresponding to an end cap 16. Thus, a housing 12 may gradually taper from one end to the other to provide a desired draft.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. 

What is claimed and desired to be secured by United States Letters Patent is:
 1. An inflator comprising: a housing; a rotor contained within the housing, the rotor defining a central axis and comprising a first circuit of fan blades and a second circuit of fan blades, the first and second circuits of fan blades respectively generating centrifugal and axial flows of air when the rotor is rotated about the central axis; a stator contained within the housing, the stator comprising a third circuit of fan blades extending radially away from the central axis; an electric motor contained within the housing, the electric motor generating relative rotation of the rotor with respect to the stator about the central axis; and at least one battery contained within the housing, the at least one battery powering the electric motor.
 2. The inflator of claim 1, wherein the housing comprises an inlet and an outlet.
 3. The inflator of claim 2, wherein: the first circuit of fan blades is downstream from the inlet; the second circuit of fan blades is downstream of the first circuit of fan blades; the third circuit of fan blades is downstream of the second circuit of fan blades; and the outlet is downstream of the third circuit of fan blades.
 4. The inflator of claim 3, further comprising a restrictor positioned between the inlet and the first circuit of fan blades, the restrictor requiring that air flowing from the inlet to the outlet pass through a central aperture.
 5. The inflator of claim 4, wherein the central aperture has a diameter that is less than or equal to an outer diameter of the first circuit of fan blades.
 6. The inflator of claim 4, wherein the central aperture has a diameter that is less than or equal to an inner diameter of the second circuit of fan blades.
 7. The inflator of claim 3, wherein: the rotor further comprises a central hub having a circumference; the first circuit of fan blades is located inboard of the circumference; and the second circuit of fan blades is located outboard of the circumference.
 8. The inflator of claim 3, wherein: the rotor further comprises a central hub having a front face and a side wall; the first circuit of fan blades extends axially from the front face; and the second circuit of fan blades extends radially from the side wall.
 9. An inflator comprising: an inlet; a rotor defining a central axis and comprising a first circuit of fan blades and a second circuit of fan blades; the rotor wherein the first circuit of fan blades is downstream of the inlet and the second circuit of fan blades is downstream of the first circuit of fan blades; the rotor wherein the first circuit of fan blades are shaped to generate a primarily centrifugal flow of air when the rotor is rotated about the central axis; the rotor wherein the second circuit of fan blades are shaped to generate a primarily axial flow of air when the rotor is rotated about the central axis; a stator comprising a third circuit of fan blades extending radially away from the central axis; the stator wherein the third circuit of fan blades is downstream of the second circuit of fan blades; and an outlet downstream of the third circuit of fan blades.
 10. The inflator of claim 9, further comprising an electric motor connected to generate relative rotation of the rotor with respect to the stator about the central axis.
 11. The inflator of claim 9, further comprising a restrictor positioned between the inlet and the first circuit of fan blades, the restrictor requiring that air flowing from the inlet to the outlet pass through a central aperture.
 12. The inflator of claim 11, wherein the central aperture has a diameter that is less than or equal to an outer diameter of the first circuit of fan blades.
 13. The inflator of claim 11, wherein the central aperture has a diameter that is less than or equal to an inner diameter of the second circuit of fan blades.
 14. The inflator of claim 9, wherein: the rotor further comprises a central hub having a circumference; the first circuit of fan blades is located inboard of the circumference; and the second circuit of fan blades is located outboard of the circumference.
 15. The inflator of claim 9, wherein: the rotor further comprises a central hub having a front face and a side wall; the first circuit of fan blades extends axially from the front face; and the second circuit of fan blades extends radially from the side wall.
 16. A method comprising: obtaining an inflator comprising an inlet, a rotor defining a central axis and comprising a first circuit of fan blades and a second circuit of fan blades, a stator comprising a third circuit of fan blades extending radially away from the central axis, an electric motor configured to provide relative rotation of the rotor with respect to the stator about the central axis, and an outlet; powering the electric motor to generate a flow of air from the inlet to the outlet; effecting, by the first circuit of fan blades during the powering, a centrifugal compression on the flow of air; and effecting, by the second circuit of fan blades during the powering, an axial compression on the flow of air.
 17. The method of claim 16, wherein the centrifugal compression precedes the axial compression.
 18. The method of claim 17, wherein: the rotor further comprises a restrictor positioned between the inlet and the first circuit of fan blades; and the restrictor comprises a central aperture having a diameter that is less than a minimum inner diameter of the inlet.
 19. The method of claim 18, further comprising requiring the flow of air to pass through a central aperture.
 20. The method of claim 19, wherein the central aperture has a diameter that is (1) less than or equal to an outer diameter of the first circuit of fan blades or (2) less than or equal to an inner diameter of the second circuit of fan blades. 